Electric switch



Nov. 26, 1946. W. J. KELLEIGH 2,411,576

ELECTRIC SWITCH Filed Aug. 4,v 1943 Patented Nov. 26, 1946 UNITED STATESPATENT OFFICE ELECTRIC SWITCH Waldo J. Kelleigh, Wayland, Mass.,assigner to General Control Company, Cambridge, Mass., a corporation ofMassachusetts Application August 4, 1943, Serial No. 497,314

S Claims. 1

This invention relates to electric switches and more particularlyswitches of the so-called telephone type adapted to be mounted in aswitchboard panel with nothing but the handle or key projecting from theface of the board, each switch comprising a frame, a contact block, aplurality of groups of Contact springs mounted on the block and anactuator for operating the contacts.

Objects of the present invention are to provide a switch which is simpleand economical to manufacture, which is durable and reliable in use,which can -be readily converted from a locking type in which the keyremains in operative position until returned to neutral position to thenon-- locking type in which the key remains in operative position onlyso long as it is held in that position by hand, which has a long life,which electrostatically shields opposite groups of contacts from eachother, which is self-aligning in the process of assembling the partstogether, and which is generally superior to prior switches of thecharacter referred to.

In-one aspect the invention involves a frame having a supporting wallwith a group of spring contacts mounted on one side of the wall and anactuator movably mounted on the other side of the wall, the actuatorhaving a roller or other operator extending through an opening in thewall for operating the contacts, and a springactuated detent mounted onthe first side of the wall for engagement with the actuator through anopening in the wall yieldingly to hold the actuator in one or more ofthe positions to which it is moved.

In a more specific aspect the invention involves two walls with a spacetherebetween for the aioresaid actuator and with a support for switchcontacts on both sides of the juxtaposed walls. When employing two frameplates a spring-actuated detent is preferably provided on each plate,the two detents pinching the actuator therebetween through openings inthe plates. By providing a detent on each side the thrusts of the twodetents tend to counteract each other thereby reducing the friction andwear on the pivot pin of the actuator or other part which controls itspath of movement. By making the actuator of variable thickness along thezone engaged by the detents the actuator is yieldingly held inpredetermined positions, as for example a neutral central position andan operating position on one or both sides of the neutral position. Byproviding the detents with rollers for rolling engagement with theactuator the friction is reduced, thereby making the switch easier tooperate and prolonging its life. By providing coil springs in- A steadof leaf springs for actuating the detents the 'springs are lessexpensive, last longer and can -be replaced more readily andeconomically. In the preferred construction the thrusts imparted to theopposite sides of the actuator by the detent springs automaticallyequalize. Thus the springs have no tendency to tip the actuator andconsequently the actuator operates with less friction.

In still another aspect the invention involves a frame having two legswith a space therebetween and a contact block tted into the space withgrooves in one or both sides of the block to receive one or both of thelegs. The contact block is preferably fastened on the frame by means ofa screw or other fastener extending through the block lengthwise of thelegs into engagement with the frame. When the frame is in the form oftwo plates as aforesaid, the plates are held together by the grooves inthe contact block, and by making a fairly snug fit between the block andplates the parts are self-aligning when the block is slipped into theslots in the plates.

For the purpose of illustration a typical embodiment of the invention isshown in the accompanying drawing in which Fig. 1 is a side elevation;

Fig. 2 is an end elevation;

Fig. 3 is a section on line 3--3 of Fig. 1;

Fig. 4 is a bottom view;

Fig. 5 is a section on line 5 5 of Fig. 1;

Fig. 6 is a perspective view of the actuator;

Fig. 7 is a perspective view of one of the spring detents;

Fig. 8 is a side elevation of a slight modication; and

Fig. 9 is a section on line 9-9 of Fig. 1.

The particular embodiment of the invention chosen for the purpose ofillustration comprises two frame plates l and 2 which are offset at 3 sothat, with their lower ends abutting each other face to face, the upperends are separated by a space il, the tips of the upper ends being bentoutwardly to form flanges Ei and 'l for mounting the switch on aswitchboard or the like. The upper ends of the plates may beinterconnected by rivets S and the lower ends may also be rivetedtogether as indicated at Q. Extending upwardly from the bottom edges ofthe frame plates are slots Il (Figs. 1 and 4) dividing the frame intotwo legs, and mounted in these slots is a Contact block l2, the oppositesides of the block having grooves to receive the edges of the slots.From the upper ends of the slots H to the shoulder 3, the plates arepressed outwardly as indicated at 3 I3 to form opposing grooves whichtogether form a cylindrical socket. After the plates are securedtogether this socket is threaded to receive a screw lil which extendsthrough a vertical opening l5 in the block l2 and then threads into thesocket. Mounted on the opposite sides of the contact block l2 are fourlgroups 2l, 22, 23 and 24 of contact springs, the springs being held byscrews p26 with a layer 2l of insulation on eachside of each spring. Theheads of the screws seat on a plate 23 and the other ends of the screwsare threaded into a plate 29. In the illustration each group of contactsprings comprises a central spring which is somewhat longer than theother two springs and which is engageable with either of the other twosprings. As shown in the drawing the center spring usually contacts withthe inner spring when the key is in the central neutral position shownin Figs. 1 and 3 and, when the key is moved to one of its operativepositions, the central spring is moved out of contact with the innerspring in to contact with the outer spring, The actuator for operatingthe contact spring comprises a cam plate 3l which is pivotally mountedin the space il by means of a pivot pin 32. The upper edge of the camplate is provided with a threaded extension 33 to receive the handle tl.Mounted in opening 3B in the cam plate are tubes which project laterallythrough the arcuate slots 38 in the plates I and 2. Mounted on theprojecting ends of the tube are rollers 4| for operating the middlesprings of the groups, the rollers being held on the tubes by means ofscrews i2 threaded into the ends of the tubes. The actuator is alsoprovided with an opening i3 (Fig. l) to receive a stop pin for use inthe event that it is desired to prevent movement of the actuator in onedirection (counterclockwise in Fig. l) By omitting the pin M the key 34may be thrown either to the right or to the left.

For the purpose of holding the actuator in its central position or inits right or left operating position, the lower end of the plate 3l isshaped so that it is thin in the middle 6G and at the ends tl', butrelatively thick in between, the thickness varying gradually fromminimumV to maximum and vice versa. MountedA on the outside of the lowerend of the plate 22 are detent holders 5i having legs 52 which straddlethe raised portions I3 of the plates l and 2. At their upper free endsthe detent holders are providedwith openings '5ft tor accommodate therollers 56 which rotate o-n pins El seating in the semi-circular`recesses 58 above and below the openings 5e. The detent holders arepressed inwardly by coil springs 'Il (Fig, 9), the inner ends of thesprings bearing on thevouter faces of the holdersand the outer ends ofthe springs reacting against a reactor which, inthe illustration,comprises a pin l2 having headson its opposite ends and washers 73between the heads and springs. The pin slides freely in a sleeve lllwhich extends through openings in the plates l and 2 and openings l5(Fig. 7) in the detent holders, the sleeve being fast to the plates land Zbut fitting the openings l5 loosely. Thusthe lower end of theactuator is pinched betweenthe rollers 55, the holders 5i substantiallymeeting the outer faces of the plates and 2 whenA the rollers 5t engageparts i6 and lll of minimum thickness and springing outwardly as therollers ride over the thicker parts of the actuator. Thus the actuatoris yieldingly held in the mid-position or in either one of the operativepositions. By virtue of the spring arrangement the lateral thrusts ofthe detents on the actualil 4 tor are balanced and there is no tendencyto tip the actuator out of its plane of movement. In this way frictionis minimized, whereby the actuator moves with ease and with little wear.

The plates l and 2 are provided with opposed openings El and 62 for usein the event that it is desired to prevent the actuator from moving farenough to the right or left to be held in operative position by thespring detent. Thus Fig. 8 shows a rivet il?, in the opening 62 forlimiting the movement of the key 313 to the left, Thus when the key isreleased it returns to neutral position instead of remaining in theleft-hand operative position.

From the foregoing it will be understood that the modiiication shown inFig. 8 differs from the construction of the preceding iigures only inthat a rivet 53 has been mounted in the opening 62. lt will' be evidentthat by making the frame l--2 of metal it electrostatically shields thetwo groups oi contacts 2l and 22 from the two groups and 2li, therebyavoiding interference between the currents in the circuits on oppositesides of the switch. Ey virtue of the double-plate construction a veryrigid frame can be made with relatively thin stock. This constructionalso affords a convenient and effective way of mounting the actuator Si,namely by an ordinary rivet so as to be self-centering without providingshoulders on the rivet. By virtue of the telescope interengagementbetween the switch block and the frame plates the parts areself-aligning in the process of manufacture and after being assembledthe engagement of the edges of the frame plates in the grooves of theswitch block l2 serve to hold the two plates together. The-uniqueconstruction also permits the parts to be held together by the singlescrew le. Moreover both the actuator and the contact block are simple inshape and economical to manufacture. For eX- ample, the actuator may becoined and the block may be die cast. By pinching the actuator betweentwoV spring detents the thrusts of the detents counteract each other andby providing the rollers 5t the friction and wear are minimized. Theopenings Si and S2 and the pins or rivets 63 aiord a convenient way ofchanging a switch from the locking to the non-locking type and viceversa. For example, the switches may be carried in stock without pins 63and then, in those switches to be made non-locking, pins 63 may beinserted. Likewise the keys may be readily changed from two-way toone-way operation by inserting pins in the openings 43,

It should be understood that the present disclosure is for the purposeof` illustration only and that this invention includes all modificationsand equivalents which fall within. the scope of the appended claims.

I claim:

1. An electric switch comprising contacts, a contact actuator movablefrom a normal position to an advanced position, detents engagingopposite sides of the actuator for holding it in advanced position, aspring reactor extending transversely of the actuator adjacent thereto,the reactor having an abutment outside each detent, and a compressionspring outside each detent, each spring being interposed between one ofsaid abutments and one of said detents, said reactor being free to movetransversely of the actuator, whereby the thrusts of said springsagainst said detents are automatically equalized.

2.' An electric switch comprising contacts, a contact actuator movablefrom a normal position to an advanced position, detents engagingopposite sides of the actuator for holding it in ad vanced position, apin extending transversely ci the actuator adjacent thereto, the pinhaving an abutment outside each detent, and a compression spring outsideeach detent, each spring seing interposed between one of said abutmentsand o -e of said detents, said pin being free to move tran, versely oithe actuator, whereby the thrusts ci said springs against said detentsare automatically equalized.

3. An electric switch comprising contacts, a contact actua-tor movablefrom a normal position to an advanced position, detents engagingopposite sides of the actuato-r for holding it in advanced position, apin extending transversely oi the actuator through openings in saiddetents, the pin having an abutment outside each detent, and acompression spring outside each detent, each spring being interposedbetween one of said abutments and one of said detents, said pin beingfree to move transversely of the actuator in said openings, whereby thethrusts of said springs against said detents are automaticallyequalized.

4. An electric switch comprising contacts, a contact actuator movablefrom a normal position to an advanced position, detents engagingopposite sides of the actuator for holding it in advanced position, asleeve extending through openings in said detents and fitting looselythereiv, means for supporting the sleeve intermediate the detents, a pinextending through said sleeve projecting from each end thereof, thehaving an abutment beyond each end of the sleeve,

a compression spring surrounding the pin outside each detent, eachspring being interposed between one of said abutments and one of said detents, said pin being iree to slide lengthwise in said sleeve, wherebythe thrusts or said springs against said detents are automaticallyequalized.

5. An electric switch comprising a traine having two juxtaposed wallswith a space therebetween, a group of spring contacts mounted outsideeach wall for movement relatively thereto,

an actuator mounted in said space for movement parallel to the walls,switch operators extending from the actuator through openings in saidwalls for operating said groups respectively, spring-actuated detentsmounted outside said walls for engagement with opposite sides of saidactuator through openings in the walls yieldingly to hold the actuatorin one or more of the positions to which it is moved, a pin extendingtransversely of the actuator through openings in said detents and saidwalls, the pin having an abutment outside each detent, and a compressionspring out-- side each detent, each spring being interposed between oneof said abutments and one of said detents, said pin being free to movetransversely of the actuatoin said openings, whereby the thrusts of saidsprings against said detents are automatically equalized.

6. An electric switch comprising a frame having two juxtaposed wallswith a space therebetween, groups of spring contacts mounted outsideeach wall for movement relatively thereto, an actuator mounted in saidspace for movement parallel to the walls, switch operators extendingfrom the actuator through openings in said walls for operating saidgroups respectively, spring-actuated detents mounted outside said wallsfor engagement with opposite sides of said actuator through openings inthe walls yieidingly to hold the actuator in one or more of thepositions to which it is moved, a sleeve extending through openings insaid detents and walls, the sleeve ntting the wall openings tightly butbeing loose in the detent openings, a pin extending through said sleeveand projecting from each end thereof, the pin having an abutment beyondeach end of the sleeve, and compression spring surrounding the pinoutside each detent, each spring being interposed between one of saidabutments and one of said detents, said pin being free to slidelengthwise in said sleeve, whereby the thrusts of said springs againstsaid detents are automatically edualized.

7. An electric switch comprising two juxtaposed plates which are oisetintermediate their ends to abut each other at their lower ends andprovide a space therebetween at their upper ends, an actuator mounted insaid space to swing parallel to the plates about transverse axis, groupsor spring contacts mounted on the outside of said plates with their freeends adjacent said space, switch operators extending from the actuatorthrough openings in the plates for operating said groups, said actuatorhaving a handle extending upwardly beyond said walls and a tail havingrecesses in its opposite sides, rolling detents engageable with saidrecesses through openings in said upper ends of the plates to hold theactuator in different positions, holders for the detents mounted on theoutside of said lower ends, a pin extending transversely of the actuatorthrough openings in said holders and the lower ends of said plates, thepin having an abutment outside each holder, and a compression springoutside each holder, each spring being interposed between one oi saidabutments and one of said holders, said pin being free to movetransversely of the actuator in said openings, whereby the thrusts ofsaid springs against said holders are automatically equalized.

S. An electric switch comprising two juxtaposed plates which are offsetintermediate their ends to abut each other at their lower ends andprovide a space therebetween at their upper ends, an actuator mounted insaid space to swing parallel to the plates about a transverse axis,groups ci spring contacts mounted on the outside of said plates inoffset relation to the vertical plane containing said axis, switchoperators extending from the actuator through openings in the plates foroperating said groups, said actuator having a handle extendinCY upwardlybeyond said walls and a depending tail having recesses in its oppositesides, rolling detents engageable with said recesses through openings inthe upper ends of said plates to hold the actuator in differentpositions, holders for the detents mounted on the outside of said lowerends, s ld detents and holders being disposed in the region of saidplane, a sleeve extending through openings in said holders and saidplates, the sleeve ntting the plate openings tightly but being loose inthe holder openings, a pin extending through said sleeve and projectingfrom each end thereof, the pin having an abutment beyond each end of thesleeve, and a compression spring surrounding the pin outside eachholder, each spring being interposed between one of said abutments andone oi said holders, said pin being free to slide lengthwise in saidsleeve, whereby the thrusts oi said springs in said holders areautomatically equalized.

WALDO J. KELLEIGH.

